Attwood Sahara Mk2 500 GPH Automatic Bilge Pump The Sahara Mk2 is the most reliable automatic bilge pumps Attwood has ever designed. The patented X-Air impeller is engineered to to force air bubbles trapped in the hose and underside the pump out of the pipework. This prevents the pump from running dry which can damage the bilge pump. The SteadySwitch is designed with buoyancy control, this helps reduce cycling and extends the bilge pumps working life. This pump is designed for both fresh and sal